Arachnids are a class of arthropods that includes spiders, ticks, mites, and scorpions, which have segmented bodies that include two regions, but no antennae or wings. The anterior region of the arachnid includes four pairs of legs. Arachnida includes three principal orders: Araneina, or spiders; Arthrogastra, including scorpions, and Acarina, or mites and ticks. Ticks are blood-sucking acarid ectoparasites, which penetrate the skin of their host and feed on its blood. Ticks attack all groups of terrestrial vertebrates. Ticks are important vectors of a number of diseases, including Lyme disease, Rocky Mountain spotted fever, tularaemia, babesiosis, relapsing fever, erlichiosis, Colorado Tick Fever, typhus, hemorrhagic fever, and viral encephalitis. Conventional methods of tick control rely on reducing the population of animal hosts, such as the white tail deer that act as hosts for ticks that act as Lyme disease vectors, and spraying toxic chemicals in tick-infested areas. Despite these efforts, Lyme disease has been rising in many areas of the U.S., as the number of animal hosts has increased. Effective methods for controlling ticks, which do not involve the use of dangerous chemicals, are urgently required.